New 2020 American College of Radiology ACR Appropriateness Criteria® Imaging after Mastectomy and Breast Reconstruction Variant 1: Female. Breast cancer screening. History of cancer, mastectomy side(s), no reconstruction. Procedure Appropriateness Category Relative Radiation Level US breast Usually Not Appropriate O Digital breast tomosynthesis screening Usually Not Appropriate ☢☢ Mammography screening Usually Not Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ Variant 2: Female. Breast cancer screening. History of cancer, autologous reconstruction side(s) with or without implant. Procedure Appropriateness Category Relative Radiation Level Digital breast tomosynthesis screening May Be Appropriate ☢☢ Mammography screening May Be Appropriate ☢☢ US breast Usually Not Appropriate O MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ Variant 3: Female. Breast cancer screening. History of cancer, nonautologous (implant) reconstruction side(s). Procedure Appropriateness Category Relative Radiation Level US breast Usually Not Appropriate O Digital breast tomosynthesis screening Usually Not Appropriate ☢☢ Mammography screening Usually Not Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ ACR Appropriateness Criteria® 1 Imaging after Mastectomy and Breast Reconstruction Variant 4: Female. Breast cancer screening. High-risk, bilateral prophylactic mastectomy, no reconstruction. Procedure Appropriateness Category Relative Radiation Level US breast Usually Not Appropriate O Digital breast tomosynthesis screening Usually Not Appropriate ☢☢ Mammography screening Usually Not Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ Variant 5: Female. Breast cancer screening. High-risk, bilateral prophylactic mastectomy with autologous reconstructions. Procedure Appropriateness Category Relative Radiation Level US breast Usually Not Appropriate O Digital breast tomosynthesis screening Usually Not Appropriate ☢☢ Mammography screening Usually Not Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ Variant 6: Female. Breast cancer screening. High-risk, bilateral prophylactic mastectomy with nonautologous (implant) reconstructions. Procedure Appropriateness Category Relative Radiation Level US breast Usually Not Appropriate O Digital breast tomosynthesis screening Usually Not Appropriate ☢☢ Mammography screening Usually Not Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ ACR Appropriateness Criteria® 2 Imaging after Mastectomy and Breast Reconstruction Variant 7: Female. Palpable lump or clinically significant pain on the side of the mastectomy without reconstruction. Initial imaging. Procedure Appropriateness Category Relative Radiation Level US breast Usually Appropriate O Digital breast tomosynthesis diagnostic May Be Appropriate ☢☢ Mammography diagnostic May Be Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ Variant 8: Female. Palpable lump or clinically significant pain on the side of the mastectomy with reconstruction (autologous or nonautologous). Initial imaging. Procedure Appropriateness Category Relative Radiation Level US breast Usually Appropriate O Digital breast tomosynthesis diagnostic May Be Appropriate ☢☢ Mammography diagnostic May Be Appropriate ☢☢ MRI breast without and with IV contrast Usually Not Appropriate O MRI breast without IV contrast Usually Not Appropriate O Sestamibi MBI Usually Not Appropriate ☢☢☢ FDG-PET breast dedicated Usually Not Appropriate ☢☢☢☢ ACR Appropriateness Criteria® 3 Imaging after Mastectomy and Breast Reconstruction IMAGING AFTER MASTECTOMY AND BREAST RECONSTRUCTION Expert Panel on Breast Imaging: Samantha L. Heller, MD, PhDa; Ana P. Lourenco, MDb; Bethany L. Niell, MD, PhDc; Nicolas Ajkay, MDd; Ann Brown, MDe; Elizabeth H. Dibble, MDf; Aarati D. Didwania, MDg; Maxine S. Jochelson, MDh; Katherine A. Klein, MDi; Tejas S. Mehta, MD, MPHj; Helen A. Pass, MDk; Ashley R. Stuckey, MDl; Mary E. Swain, MDm; Daymen S. Tuscano, MDn; Linda Moy, MD.o Summary of Literature Review Introduction/Background Mastectomy may be performed to treat breast cancer [1] with some authors reporting increasing rates of mastectomy relative to breast conservation in the United States [2-4]. Mastectomy may also be performed as a prophylactic approach in women with a high lifetime risk of developing breast cancer. Mastectomy techniques have changed over time with radical mastectomy replaced by modified radical mastectomy and with options such as skin-sparing and nipple-sparing procedures now available [5]. In addition, mastectomies may be performed with or without reconstruction. Reconstruction approaches differ and may be autologous, involving a transfer of tissue (skin, subcutaneous fat, and muscle) from other parts of the body to the chest wall. Examples of autologous reconstruction include latissimus dorsi flaps, transverse rectus abdominis myocutaneous (TRAM) flaps, and variants such as deep inferior epigastric perforator flaps [1]. Reconstruction may also involve implants. Implant reconstruction may occur as a single procedure or as multistep procedures with initial use of an adjustable tissue expander allowing the mastectomy tissues to be stretched without compromising blood supply. Ultimately, a full-volume implant, which may be saline, silicone, or both, will be placed. Implant reconstruction often involves the placement of acellular matrix, which can increase risk of seroma formation and occasionally is visible on imaging. Reconstructions with a combination of autologous and implant reconstruction may also be performed. Other techniques such as autologous fat grafting may be used to refine both implant and flap-based reconstruction [6]. Although most of the breast tissue is removed after mastectomy, recurrence may occur in residual tissue. The majority of recurrences in the reconstructed breast will be found in the skin and the subcutaneous tissues followed by recurrences deep to the pectoralis muscle [7]. Recurrence rates are reported to be approximately 1% to 2% annually for both mastectomy and mastectomy with reconstruction, and overall recurrence has been reported at between 2% to 15% and has been noted to vary based on the initial cancer type and stage as well as follow-up period of the study [5,7-13]. Clinical evaluation has been a mainstay of evaluation of the postmastectomy breast [4], and the appropriate surveillance imaging strategy for patients with a history of mastectomy with or without reconstruction is an evolving topic, with evidence predominantly drawn from small retrospective studies. Finally, women who have undergone mastectomy with or without reconstruction may present with symptomatic concerns, both in the immediate postoperative period and later. Sequalae of the surgery, such as hematomas, infections, and most commonly in the early postoperative period, fat necrosis [7], may present as palpable findings. Recurrent disease may also present as a palpable lump [7,14]. Initial Imaging Definition Imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when: • There are procedures that are equivalent alternatives (ie, only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care) OR aNew York University School of Medicine, New York, New York. bPanel Chair, Alpert Medical School of Brown University, Providence, Rhode Island. cPanel Vice-Chair, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. dUniversity of Louisville School of Medicine, Louisville, Kentucky; Society of Surgical Oncology. eUniversity of Cincinnati, Cincinnati, Ohio. fAlpert Medical School of Brown University, Providence, Rhode Island. gNorthwestern University Feinberg School of Medicine, Chicago, Illinois; American College of Physicians. hMemorial Sloan Kettering Cancer Center, New York, New York. iUniversity of Michigan, Ann Arbor, Michigan. jBeth Israel Deaconess Medical Center, Boston, Massachusetts. kStamford Hospital, Stamford, Connecticut; American College of Surgeons. lWomen and Infants Hospital, Providence, Rhode Island; American College of Obstetricians and Gynecologists. mRadiology Associates of Tallahassee, Tallahassee, Florida. nCentral Oregon Radiology Associates, Bend, Oregon.